In electric power switchgears, bounce generally occurs between a pair of contacts when the contacts in an opened state are switched on (closed) at a given speed. The bounce is generally called chattering. The contacts have a potential difference therebetween, and hence an electric arc is generated between the contacts due to the chattering. As a result, the surface of the contact is roughen or worn out, thereby causing increase in contact resistance between the contacts. Further, when the contacts are separated from each other for a long period of time during the chattering, the contacts may be fused. In order to address those problems, it is important to suppress the chattering.
In general, the switch-on action is a collision event. Therefore, in order to suppress the bounce, it is effective to use a mechanism having a high damping effect, such as a rubber, thereby dissipating energy. Under a severe outdoor environment where the switchgear is used, however, deterioration of this mechanism becomes a problem, and hence this mechanism cannot be used.
In view of the above, hitherto, there is known a switchgear in which a stationary contact is supported on a support base through intermediation of laminated plates, which are a plurality of plates laminated on each other, thereby dissipating energy (see, for example, Patent Literature 1).